Action: methysergide’s main action is to antagonize (block) specific serotonin receptors, particularly the 5-HT2A and 5-HT1D receptors. Doing so interferes with the effects of serotonin, a neurotransmitter that contributes to various physiological functions, including mood regulation, blood vessel constriction, and gastrointestinal function. The blocking of 5-HT2A receptors can impact hallucinogenic effects, while the blocking of 5-HT1D receptors is particularly relevant in migraines.
Migraine Prevention: methysergide is most used for the prevention of severe migraines. By blocking the 5-HT1D receptors located on blood vessels, it helps to reduce the dilation of blood vessels in the brain that is associated with migraines. It can lead to a decrease in the frequency and intensity of migraine attacks.